Low Vibration Fan

ABSTRACT

A low vibration fan including a housing, a driving member and a fan wheel is provided. The housing has an outer frame and a base, wherein the outer frame has two openings, a positioning rim, and a guiding channel linking the two openings, wherein the base couples with the positioning rim, and wherein a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim. The driving member is mounted on the base. The fan wheel couples with the driving member rotatably. Accordingly, the radial buffer gap can largely reduce the vibration transmitted from the base to the outer frame.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a fan and, more particularly, it relates to a low vibration fan.

2. Description of the Related Art

A conventional fan usually includes a frame receiving a rotatable fan wheel inside. When the conventional fan is received inside an electronic system, an air current induced by the rotation of the fan wheel can provide a desirable cooling effect to electronic elements of the electronic system.

However, since there is vibration in the rotation of the fan wheel usually, said vibration can easily transmit to the casing of the electronic system via the frame. This kind of vibration not only induces noises, but also lowers the operational stability of the electronic system as well as accelerates the deterioration of the circuit joints inside the electronic system, and thus shortens the lifetime of this electronic system.

Therefore, referring to FIG. 1, an invention entitled as “Fan Housing,” with a Taiwan patent number of 1271475, is provided to show a conventional low vibration fan 9. This conventional fan 9 includes a frame 91 inwardly connecting with a base 93 via a plurality of ribs 92, with the base 93 adapted to couple with an impeller 94 rotatable thereon. Specifically, the frame 91 is in a square shape and there are four rubber columns 95 stand on the corners of the square respectively for the frame 91 to couple with a housing 96 of an electronic system, such as a computer server, through the rubber columns 95. Therefore, the rubber column 95 is able to damp the vibration from the impeller 94 when the impeller 94 operates.

However, the vibration-damping performance of the rubber column 95 is quite limited, and thus the housing 96 still suffers the vibration caused by the operated impeller 94 since said vibration is continuously transmitted to the frame 91 via a route formed by the ribs 92 due to the rotatable coupling between the impeller 94 and the base 93. Therefore, the remaining vibration can still lower the operational stability of the electronic system, induce noises, and shorten the lifetime of this electronic system when the conventional fan 9 is installed in this electronic system and operated.

Moreover, the said remaining vibration may also cause a fault or failure in reading operation of a hard disk in the electronic system. As a result, it is necessary to improve the conventional fan.

SUMMARY OF THE INVENTION

It is therefore the objective of this invention to provide a low vibration fan to efficiently break a route for vibration transmission, to largely damp the vibration caused by operation of a fan wheel, and to maintain operational stability and lower noise of an electronic system.

One embodiment of the invention discloses a low vibration fan, which includes a housing, a driving member and a fan wheel. The housing has an outer frame and a base, wherein the outer frame has two openings, a positioning rim, and a guiding channel linking the two openings, the base couples with the positioning rim, the positioning rim of the outer frame has a minimal inner diameter, and the base has a maximal outer diameter smaller than or equal to the minimal inner diameter. The driving member is mounted on the base. The fan wheel couples with the driving member rotatably. Preferably, the positioning rim has an axial shoulder for the base to abut against. Preferably, a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim. In a preferred form shown, the outer frame of the fan is a hollow body, the positioning rim is formed on an end section of the guiding channel defining one of the two openings, the base of the housing includes a seat, a plurality of connecters and a coupling member, the plurality of connecters connects with the seat by one end and the coupling member by another end, the base couples with the positioning rim by the coupling member, the coupling member abuts against the axial shoulder, and an outer periphery of the coupling member is spaced from the inner periphery of the positioning rim by the radial buffer gap.

In a preferred form shown, the outer frame of the housing has a hollow body, a plurality of connecters and a coupling member, the plurality of connecters connects with an inner periphery of the hollow body by one end and the coupling member by another end, the base is a seat, the positioning rim is formed on an end of the coupling member, the axial shoulder is arranged on the inner periphery of the positioning rim, the base couples with the positioning rim and abuts against the axial shoulder, and the outer periphery of the base is spaced from the inner periphery of the positioning rim by the radial buffer gap.

In a preferred form shown, the outer frame of the housing is a hollow body, the positioning rim is formed on an end section of the guiding channel defining one of the two openings, the base of the housing includes a seat and a plurality of connecters, the plurality of connecters connects with the seat by one end and the positioning rim by another end, each end of the connecters connecting with the positioning rim has an axial edge abutting against an axial shoulder formed on the inner periphery of the positioning rim, as well as a radial edge spaced from the inner periphery of the positioning rim by the radial buffer gap.

In a preferred form shown, the base is coupled with the axial shoulder by adhesive.

In a preferred form shown, the low vibration fan further comprises a plurality of limiting flanges inwardly extending from the outer frame, and the base is axially engaged between the limiting flanges and the axial shoulder.

In a preferred form shown, the low vibration fan further comprises a plurality of fixing holes in the outer frame and a pressing member having a plurality of through holes in alignment with the fixing holes, wherein a plurality of fixing member passes through the plurality of through holes and fixes to inner surfaces of the plurality of fixing holes, and the base is axially sandwiched between the pressing member and the axial shoulder.

In a preferred form shown, the coupling member is a ring. In a preferred form shown, an edge of one of the two openings has a plurality of engaging notches and the base has a plurality of engaging protrusions corresponding to and able to insert into the engaging notches.

In a preferred form shown, the positioning rim of the outer frame has a plurality of connecting grooves and the base has a plurality of elastic hooks corresponding to and inserted in the plurality of connecting grooves.

When the low vibration fan is installed in an electronic system, based on the feature that the maximal outer diameter of the base is not larger than the minimal inner diameter of the outer frame (preferably including the radial buffer gap formed between the outer frame and the base), the vibration that is caused during the operation of the impeller and is transferred from the base to the outer frame can be significantly reduced. As a result, the noise is reduced and the service life of the electronic system is prolonged.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a cross-sectional view of a conventional fan.

FIG. 2 is an exploded and perspective view of a low vibration fan according to a first embodiment of the invention.

FIG. 3 is a cross-sectional view of the low vibration fan according to the first embodiment.

FIG. 4 is a partially enlarged and cross-sectional view of the low vibration fan according to the first embodiment.

FIG. 5 is an exploded and perspective view of the low vibration fan according to the first embodiment with a pressing member.

FIG. 6 is a cross-sectional view of the low vibration fan according to the first embodiment with a pressing member.

FIG. 7 is an exploded and perspective view of the low vibration fan according to the first embodiment with engaging notches and engaging protrusions.

FIG. 8 is a partially enlarged and cross-sectional view of the low vibration fan according to the first embodiment with engaging notches and engaging protrusions.

FIG. 9 is a cross-sectional view of a low vibration fan according to a second embodiment of the invention.

FIG. 10 is a partially enlarged and cross-sectional view of the low vibration fan according to the second embodiment.

FIG. 11 is an exploded and perspective view of the low vibration fan according to the second embodiment with connecting grooves and elastic hooks.

FIG. 12 is a partially enlarged and perspective view of one pair of the connecting grooves and elastic hooks of the low vibration fan according to the second embodiment.

FIG. 13 is an exploded and perspective view of a low vibration fan according to a third embodiment of the invention.

FIG. 14 is a cross-sectional view of the low vibration fan according to the third embodiment.

FIG. 15 is a partially enlarged and cross-sectional view of the low vibration fan according to the third embodiment.

In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the term “first,” “second,” “third,” “inner,” “outer” and similar terms are used hereinafter, it should be understood that these terms refer only to the structure shown in the drawings as it would appear to a person viewing the drawings, and are utilized only to facilitate describing the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 2 and 3, a first embodiment of a low vibration fan of the present invention is shown, which includes a housing 1, a driving member 2 and a fan wheel 3. The housing 1 is in a structure for guiding air flows to enter and exit said low vibration fan, such as a housing structure of an axial fan, a centrifugal fan, or an advection fan (which guides air current to flow in and out of the fan in a radial direction), which is shown as that of an axial fan for example in the following illustration.

The driving member 2 is coupled inside the housing 1. The fan wheel 3 is rotatably mounted on the driving member 2 so as to be turned by the driving member 2. Specifically, a shape of the housing 1 is not limited as long as this shape is capable of receiving the driving member 2 as well as the fan wheel 3. For instance, the housing 1 can be a polygonal shape, a circular shape or an elliptic shape. In the following embodiments, the housing 1 is in a rectangular shape.

The housing 1 includes an outer frame 11 and a base 12. The outer frame 11 has two openings 111, 112 and a guiding channel 113 linking these two openings 111, 112, wherein any one of the openings 111, 112 serves as an air inlet and the other one serves as an air outlet, such as the opening 111 serves as the air inlet while the opening 112 serves as the air outlet, and vice versa. The outer frame 11 has a positioning rim 114 with an axial shoulder 115 forming a supporting surface facing the opening 112. Therefore, the base 12 can be inserted in and surrounded by the positioning rim 114 and abut against the supporting surface of the axial shoulder 115 directly or indirectly. Please refer to FIG. 3 and further to FIG. 4. Preferably, a buffering pad 5 is sandwiched between the base 12 and the axial shoulder 115. In addition, the positioning rim 114 of the outer frame 11 has an inner periphery with a minimal inner diameter “d1.” The base 12 has an outer periphery with a maximal outer diameter “d2” not larger than, namely being smaller than or equal to, the minimal inner diameter “d1,” so as to preferably form a radial buffer gap “D” between the outer periphery of the base 12 and the inner periphery of the positioning rim 114. The space between the inner periphery of the positioning rim 114 and the outer periphery of the base 12 may totally or partially serve as the radial buffer gap “D.”

In this first embodiment, the outer frame 11 of the housing 1 is a hollow body 11 a, the positioning rim 114 is formed on an end section of the guiding channel 113 defining the opening 112, and the axial shoulder 115 is arranged on the inner periphery of the positioning rim 114. The base 12 of the housing 1 includes a seat 12 a, a plurality of connecters 12 b and a coupling member 12 c. The plurality of connecters 12 b locates between the seat 12 a and the coupling member 12 c while connecting with the seat 12 a by one end and the coupling member 12 c by another end. Each of the connecters 12 b is in the shape of a rib and, preferably, is a vane-shaped rib. The coupling member 12 c is in the shape of a ring around the seat 12 a and the plural connecters 12 b. Thereby, as shown in FIGS. 3 and 4, the base 12 couples with the positioning rim 114 by the coupling member 12 c, with the coupling member 12 c abutting against the supporting surface of the axial shoulder 115, and with an outer periphery of the coupling member 12 c being spaced from the inner periphery of the positioning rim 114 by the radial buffer gap “D.”

The base 12 can be coupled with the positioning rim 114 of the outer frame 11 by adhesion, hooking or screwing. For example, the base 12 can be coupled with the axial shoulder 115 by adhesive and maintain the radial buffer gaps “D” between the outer periphery of the coupling member 12 c and the inner periphery of the positioning rim 114. However, in another example, as shown by FIGS. 3 and 4, there can be a plurality of limiting flanges 41 inwardly extending from the outer frame 11, preferably from the inner periphery of the positioning rim 114, so that the base 12 can rest in the positioning rim 114 while the base 12 is pressed toward the axial shoulder 115 by an external force, axially passes through the limiting flanges 41, and is axially engaged between the limiting flanges 41 and the axial shoulder 115. In addition, in a further example shown by FIGS. 5 and 6, there can be a plurality of fixing holes 42 in the outer frame 11 and around the opening 112 while a pressing member 43 having a plurality of through holes 431 in alignment with the fixing holes 42 presses the base 12 toward the axial shoulder 115 of the outer frame 11. Therefore, the base 12 is axially sandwiched between the pressing member 43 and the axial shoulder 115 when a plurality of fixing member 44, such as screws, passes through the plurality of through holes 431 and fixes to the inner surfaces of the plurality of fixing holes 42. Moreover, in further another example shown by FIGS. 7 and 8, it is preferable that an edge of the opening 112 of the outer frame 11 has a plurality of engaging notches 451 and the base 12 has a plurality of engaging protrusions 452 corresponding to and able to insert into the said plurality of engaging notches 451. Therefore, with the engagement of the engaging notch 451 and protrusion 452, the step for coupling the base 12 with the outer frame 11 can be easy.

The driving member 2 is mounted on the base 12 of the housing 1, and the fan wheel 3 is rotatably coupled with the driving member 2. With the rotation of the fan wheel 3, an air current can be induced and pass through the guiding channel 113 by entering via one of the openings 111, 112 and existing via the other one of them, such as sequentially flowing through the opening 111, guiding channel 113 and opening 112. The driving member 2 may include elements for turning the fan wheel 3, such as silicon steel plates, stator coils and a control circuit board.

Referring to FIGS. 9 and 10, a second embodiment of the low vibration fan of the present invention is shown, which is similar to that of the first embodiment except for the following structural difference. In this second embodiment, the outer frame 11 of the housing 1 includes a hollow body 11 a, a plurality of connecters 11 b and a coupling member 11 c. The plurality of connecters 11 b locates between the hollow body 11 a and the coupling member 11 c while connecting with an inner periphery of the hollow body 11 a by one end and the coupling member 11 c by another end.

Each of the connecters 11 b is in the shape of a rib and, preferably, is a vane-shaped rib. The coupling member 11 c is in the shape of a ring received in the hollow body 11 a. The base 12 is a seat 12 a, the positioning rim 114 is formed on an end of the coupling member 11 c, and an axial shoulder 115 is arranged on the inner periphery of the positioning rim 114.

Thereby, the base 12, the seat 12 a namely, couples with the positioning rim 114 and abuts against a supporting surface of the axial shoulder 115, and an outer periphery of the base 12 is spaced from the inner periphery of the positioning rim 114 by the radial buffer gap “D.”

Additionally, as shown in FIGS. 11 and 12, it is preferable that the positioning rim 114 of the outer frame 11 has a plurality of connecting grooves 461 and the base 12 has a plurality of elastic hooks 462 corresponding to and able to insert into the said plurality of connecting grooves 461. Therefore, the base 12 having the elastic hooks 462 can be easily coupled with the outer frame 11 having the connecting grooves 461, and thus functions of convenient assembly and anti-disengagement are accordingly provided.

Referring to FIGS. 13-15, a third embodiment of the low vibration fan of the present invention is shown, which is similar to the example, shown in FIGS. 5 and 6, of the first embodiment except that the coupling member 12 c of the base 12 in the first embodiment is omitted. As a result, the plurality of connecters 12 b connects with the seat 12 a by one end and the positioning rim 114 by another end. As shown by FIG. 15, each end of the connecters 12 b connecting with the positioning rim 114 has an axial edge 121 b abutting against the axial shoulder 115 and a radial edge 122 b spaced from the inner periphery of the positioning rim 114 by the radial buffer gap “D.”

In sum, with the above illustrated embodiments of the low vibration fan, since the position of the base 12 is axially fixed to the outer frame 11 and having a maximal outer diameter “d2” not larger than a minimal inner diameter “d1” of the positioning rim 114, the vibration caused by the operation of the fan wheel 3 and transmitted to the base 12 through the driving member 2 can be efficiently isolated from the outer frame 11 of the housing 1 by the radial buffer gap “D.” Consequently, the operational stability of an electronic system with this low vibration fan can be maintained as well as a low noise performance is acquired. Besides, even if the bases 12 are axially clamped and fixed, an efficient damping and buffering effect is still achievable for noise-reducing and lifetime prolonging as long as a damping member, such as a rubber pad, is inserted between the housing 1 and a casing of the electronic system to damp the vibration induced by the rotation of the fan wheel 3.

Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims. 

What is claimed is:
 1. A low vibration fan, comprising: a housing having an outer frame and a base, wherein the outer frame has two openings, a positioning rim, and a guiding channel linking the two openings, wherein the base couples with the positioning rim, wherein the positioning rim of the outer frame has a minimal inner diameter, and wherein the base has a maximal outer diameter smaller than or equal to the minimal inner diameter; a driving member mounted on the base; and a fan wheel rotatably coupled with the driving member.
 2. The low vibration fan as claimed in claim 1, wherein a radial buffer gap is formed between an outer periphery of the base and an inner periphery of the positioning rim.
 3. The low vibration fan as claimed in claim 2, wherein the positioning rim has an axial shoulder for the base to abut against.
 4. The low vibration fan as claimed in claim 3, wherein the base abuts against the axial shoulder via a buffering pad.
 5. The low vibration fan as claimed in claim 3, wherein the outer frame of the fan is a hollow body, wherein the positioning rim is formed on an end section of the guiding channel defining one of the two openings, wherein the base of the housing includes a seat, a plurality of connecters and a coupling member, wherein the plurality of connecters connects with the seat by one end and the coupling member by another end, wherein the base couples with the positioning rim by the coupling member, wherein the coupling member abuts against the axial shoulder, and wherein an outer periphery of the coupling member is spaced from the inner periphery of the positioning rim by the radial buffer gap.
 6. The low vibration fan as claimed in claim 3, wherein the outer frame of the housing has a hollow body, a plurality of connecters and a coupling member, wherein the plurality of connecters connects with an inner periphery of the hollow body by one end and the coupling member by another end, wherein the base is a seat, wherein the positioning rim is formed on an end of the coupling member, wherein the axial shoulder is arranged on the inner periphery of the positioning rim, wherein the base couples with the positioning rim and abuts against the axial shoulder, and wherein the outer periphery of the base is spaced from the inner periphery of the positioning rim by the radial buffer gap.
 7. The low vibration fan as claimed in claim 3, wherein the outer frame of the housing is a hollow body, wherein the positioning rim is formed on an end section of the guiding channel defining one of the two openings, wherein the base of the housing includes a seat and a plurality of connecters, wherein the plurality of connecters connects with the seat by one end and the positioning rim by another end, wherein each end of the connecters connecting with the positioning rim has an axial edge abutting against the axial shoulder formed on the inner periphery of the positioning rim, as well as a radial edge spaced from the inner periphery of the positioning rim by the radial buffer gap.
 8. The low vibration fan as claimed in claim 3, wherein the base is coupled with the axial shoulder by adhesive.
 9. The low vibration fan as claimed in claim 3, further comprising a plurality of limiting flanges inwardly extending from the outer frame, wherein the base is axially engaged between the limiting flanges and the axial shoulder.
 10. The low vibration fan as claimed in claim 3, further comprising a plurality of fixing holes in the outer frame and a pressing member having a plurality of through holes in alignment with the fixing holes, wherein a plurality of fixing member passes through the plurality of through holes and fixes to inner surfaces of the plurality of fixing holes, and wherein the base is axially sandwiched between the pressing member and the axial shoulder.
 11. The low vibration fan as claimed in claim 5, wherein the coupling member is a ring.
 12. The low vibration fan as claimed in claim 6, wherein the coupling member is a ring.
 13. The low vibration fan as claimed in claim 1, wherein an edge of one of the two openings has a plurality of engaging notches and the base has a plurality of engaging protrusions corresponding to and able to insert into the engaging notches.
 14. The low vibration fan as claimed in claim 1, wherein the positioning rim of the outer frame has a plurality of connecting grooves and the base has a plurality of elastic hooks corresponding to and inserted in the plurality of connecting grooves. 